A method and apparatus for measuring the synthetic reception pattern of an adaptive array antenna, which are divided into a hardware apparatus and a measurement method. The hardware apparatus includes a wavefront simulator, a GNSS simulator, an external controller, a signal measurement unit, and a GNSS receiver. The measurement method using the hardware apparatus includes setting a direction of arrival of jamming and calculating a weight vector, fixing weight vectors at the calculated weight vector and collecting outputs of an array antenna system for all test signals, and displaying the collected data on a grid of a 2D plane. In accordance with the present invention, a weight vector calculated under a specific jamming situation is maintained for all test signals, so that the synthetic reception pattern of the array antenna system can be measured.